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-rw-r--r--arch/x86/kvm/Kconfig1
-rw-r--r--arch/x86/kvm/mmu/spte.h5
2 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index f09f13c01c6b..1ed1e4f5d51c 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -22,6 +22,7 @@ config KVM_X86
depends on X86_LOCAL_APIC
select KVM_COMMON
select KVM_GENERIC_MMU_NOTIFIER
+ select KVM_ELIDE_TLB_FLUSH_IF_YOUNG
select HAVE_KVM_IRQCHIP
select HAVE_KVM_PFNCACHE
select HAVE_KVM_DIRTY_RING_TSO
diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h
index ccfd5a091b7a..4d2b700c26dd 100644
--- a/arch/x86/kvm/mmu/spte.h
+++ b/arch/x86/kvm/mmu/spte.h
@@ -470,9 +470,8 @@ static inline bool is_mmu_writable_spte(u64 spte)
* needs to flush at the time the SPTEs is modified, before dropping mmu_lock.
*
* Don't flush if the Accessed bit is cleared, as access tracking tolerates
- * false negatives, and the one path that does care about TLB flushes,
- * kvm_mmu_notifier_clear_flush_young(), flushes if a young SPTE is found, i.e.
- * doesn't rely on lower helpers to detect the need to flush.
+ * false negatives, e.g. KVM x86 omits TLB flushes even when aging SPTEs for a
+ * mmu_notifier.clear_flush_young() event.
*
* Lastly, don't flush if the Dirty bit is cleared, as KVM unconditionally
* flushes when enabling dirty logging (see kvm_mmu_slot_apply_flags()), and